Here’s why coffee sets your morning and your bowels in motion. 

Coffee is a staple for millions of people around the world. A cup of joe is what gets them out of bed and kicks off their days. Sound like you? Well, if you’re reading this, your morning routine is likely not the only thing that coffee sets in motion.

One study found that coffee stimulates bowel movements in as little as four minutes in nearly 30 percent of the population.

There are plenty of theories as to what causes this phenomenon. Some are rooted in truth, while some aren’t.

We tapped gut health expert and Instagram-famous gastroenterologist Dr. Will Bulsiewicz to help us separate fact from fiction:

Why Does Coffee Make You Poop?


Coffee is prized for its energizing qualities, so it makes sense that plenty of people think the high caffeine content is to blame for their post-java run to the bathroom. However, this is a common misconception: A 1990 study proved that decaffeinated coffee stimulates intestinal motility in the same way that its caffeinated counterpart does.

OK, if it’s not the caffeine, then it must have something to do with the way warm beverages affect the digestive system—right? Wrong.

If you want to test this theory, try drinking a cup of microwaved water and report back.

It’s also not the polyphenols (micronutrients that we get through certain plant-based foods) that are abundant in coffee, according to Dr. Bulsiewicz.

“As a gut health enthusiast, I would love to claim that it's the polyphenols in coffee, because they have recently been discovered to have prebiotic qualities, meaning that they can alter the gut microbiome,” he said. “But as a gastroenterologist, I know it's not possible for the polyphenols in coffee to work their way down to the colon and feed the microbes just 4 minutes after ingestion.”


Here’s the truth: Coffee can stimulate intestinal motility in some people because it releases a hormone called cholecystokinin, which then triggers the gastrocolic reflex.

“This is a well described reflex where something that hits our stomach stimulates our colon to ‘make room’ for what will be coming down the pipe,” Dr. Bulsiewicz said.

There ya have it.

Can You Prevent Coffee-Induced Pooping?

Coffee is both loved and maligned for its poop-inducing capabilities.

Sure, it’s all fine and dandy when you’re enjoying a relaxing morning at home—but what about when you’re in the car? At work or school? Or, God forbid, on a coffee date?

Unfortunately (or fortunately, depending on who you ask), there’s no magic pill you can take that will stop the coffee poops in their tracks.

However, if you’re someone who is affected by the phenomenon, you may be able to build a resistance to this particular side effect.

If you’re still having severe gastrointestinal reactions after a few weeks of drinking coffee regularly, you may want to look into what else you’re putting in your cup. Milk (or a dairy-based creamer) could certainly cause issues for coffee drinkers with lactose intolerance.

Why Does Your Pee Smell Like Coffee?

In addition to making you poop, coffee can also change how your pee smells.

Remember those polyphenols we talked about at the beginning of this article? They give coffee its signature scent.

When polyphenols are broken down in your body, they become metabolites and are released in urine.

This effect is intensified by coffee’s diuretic properties (a diuretic is something that increases urine production). Since it makes you pee more often, coffee can cause dehydration if you’re not drinking enough water.

Dehydrated urine is more concentrated that regular urine, making the coffee-scented metabolites are more noticeable.